1. Field of the Invention
This invention generally relates to a connection between a bicycle fork and a wheel securing axle of a bicycle hub. More specifically, the present invention relates to a bicycle wheel securing structure used to attach the wheel securing axle of the bicycle hub to the bicycle fork.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle.
A bicycle is generally provided with a frame and a front fork that is pivotally connected to a front end portion of the frame. The front fork basically includes a fork stem, a fork crown and a pair of fork legs. The two fork legs are arranged on opposite sides of the front wheel with the tip end portions of the fork legs being connected to a front hub arranged on the rotational center of the front wheel. The fork crown is connected to the upper end portions (i.e., opposite ends from the tip end portions) of the fork legs. The fork stem is connected to the fork crown, and is arranged to extend upwardly form the fork crown. The fork stem is supported on the front end portion of the frame in a freely rotatable manner. In some cases, the front fork is a suspension fork with each of the fork legs including an upper or inner tube and a lower or outer tube that is telescopically arranged with the upper tube. The rear part of the frame has a similar rear fork that is not pivotal like the front fork. The rear fork can be fixed to the frame (i.e. a hard tail type) to form the rear triangle of the frame or can be a suspension type rear fork attached to the frame.
Typically, the lower tip ends of the forks are provided with dropouts (open ended slots) for attaching the wheels. In the past, the ends of the hub axles were inserted into the dropouts (open ended slots) and then fastened with nuts. However, since bicycle wheels often need to be removed from the frame, e.g., whenever there is a flat tire or a need to transport the bicycle in an automobile, wheel securing mechanisms were developed in order to facilitate easier removal and reinstallation of the wheels. A typical wheel securing device includes a skewer with a threaded end having a wheel securing member mounted at the other end. The wheel securing member includes a base with a lever and a cam structure. A nut is detachably threaded onto the threaded end of the skewer after the skewer is inserted through the hub body. The fork flanges are arranged between the base of the wheel securing member and the hub body and between the nut and the hub body, respectively. Thus, the hub can be attached by clamping the fork flanges using the wheel securing lever.
While these typical wheel securing mechanisms generally work well, a tighter connection between the hub and the frame has been in demand for some riders. Thus, bicycle hubs and bicycle forks have been designed such that an axle of the hub is threadedly attached directly to the bicycle fork. An example of this type of arrangement on a front hub and front fork is disclosed in U.S. Pat. No. 6,089,675. With this type of arrangement, a knob is provided on the end of the hub axle opposite the threaded end. The knob is used to rotate the axle during installation to both tighten the axle to the front fork and to clamp one fork flange between the knob and the hub. With this type of hub, a tighter connection between the hub and the front fork is possible as compared to typical wheel securing hubs. However, because of this tighter connection, it is necessary to make the front fork stronger.
In view of the above conventional technology, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved connection between a fork and a wheel securing axle of a hub. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.